This isn't exactly what you're asking for, but the following is a script I use to backup my newsblur data locally; it uses the command-line program "curl" to execute a sequence of operations against the API. Perhaps looking at it will set you on the right track:

#!/bin/bash



if [ "x$1" = "x" -o "x$2" = "x" ]; then


    echo "${0} [password] [starred item page count]";


    exit 1;


fi



cookieJar=/tmp/nb-cookies



# login to establish an authentication cookie


login_output=$(curl --cookie-jar ${cookieJar} -d username=jsled -d password="$1" http://www.newsblur.com/api/login)


# parse my user_id from the json response


user_id=$(echo $login_output | jq '.user_id')


echo "parsed user_id [${user_id}]"



# export subscriptions as OPML


curl --cookie ${cookieJar} http://www.newsblur.com/import/opml_export -o newsblur-subscriptions.opml



# save all the pages of starred items.


for i in $(seq $2); do


    curl --cookie ${cookieJar} http://www.newsblur.com/reader/starred_stories"?page=${i}" -o starred-page-$(printf "%0.2d" ${i}).json;


done



# export my shared stories


curl --cookie ${cookieJar} http://www.newsblur.com/social/stories/${user_id}/jsled -o shared-stories.json



# cleanup


#rm ${cookieJar}